The present invention generally relates to method and apparatus for straightening warped door, and more particularly, for selectively exerting force against the warped portion of the door to pull out the warp.
In recent years, there has been an increased awareness of the need to conserve energy, and the cost of energy has risen dramatically. Heating and/or cooling a dwelling requires a great amount of energy and is, therefore, very expensive. A portion of the energy used for controlling the temperature of a dwelling is lost through the openings around doors and windows. These air leaks are more pronounced especially around warped doors. One cause of such warping is due to the variance of temperatures between the inner and outer surfaces of the door. Typically in a cold climate, a door bows outwardly during the winter months.
Several methods are known which attempt to straighten warped doors by using a variety of devices. Straightening is usually accomplished by mounting an elongate member to one surface of the warped door to exert force on the door by tensioning the elongate member between the opposite ends. The elongate member of such devices generally span the length of a warped door by some means such as single or multiple rods or cables. Generally, to secure the spanning member to the door, a variety of securing methods have been used including: securing the ends of the spanning member or members to the door; or fastening the spanning member to the door along short spaced intervals. The secured spanning member then is tensioned in some manner to straighten the door. One common way to straighten the warping is by shortening the spanning member by turnbuckles or tension bolts.
One prior art device disclosed in U.S. Pat. No. 3,471,973 to Behmlander appears to add tension to a spanning member by shortening the spanning member with a turnbuckle on a connection means between a yoke and securing clip at one end portion of a door. This device, as well as similar devices, are limited in that they are not adjustable and, therefore, do not efficiently focus pressure against a selected warped portion of the warped door.
Another prior art device disclosed in U.S. Pat. No. 2,571,142 to Lando, includes an elongate presser bar having a channel cross-section and multiple transverse openings therethrough intermediate of its ends, a pair of contact blocks slidably held on the pressure bar by channel flanges, and an elongate spindle to extend through both the regular doorknob aperture and one of the multiple openings aligned with the regular doorknob aperture. This device exerts inward pressure against the presser bar by tightening a pair of nuts secured along the length of the elongate spindle. The slidable contact blocks appear to transmit that inward pressure to the door. The clumsy channel cross-section as well as the multiple transverse openings through the presser bar are unattractive and detract from the beauty of the natural door. The complicated mounting required by this device also detracts from its convenience. Lateral grooves in the contact blocks receive the channel flanges and thus limit the contact blocks to reciprocating movement along the longitudinal axis of the elongate presser bar. The spindle connection with the presser bar and the door must be loosened even to slidingly reposition the contact blocks.
Some devices which allegedly straighten doors exert force along an elongate member between its attachment at opposite ends on the door by fasteners such as screws. Because even a limited amount of force has been known to strip out such screws, these devices are strictly limited in the amount of tension they can sustain between the opposite ends of attachment of the elongate member. Some devices try to overcome this problem by using multiple elongate members interconnected end-to-end by turnbuckles or tension bolts or by securing sections of an elongate member along the length of the warped door. Other such devices use additional screws to secure the ends of multiple elongate rods, or along a single elongate rod. Often such devices effectively become a permanent part of the door either because multiple mounting holes scar the door, or the mounting requirements are too complex to permit easy installation and removal.
Consequently, a need exists for an apparatus for straightening warped doors which is effective, efficient and economical, and which will use a minimum number of parts to produce a sufficient amount of force directly on a warped portion of the door.